Asked whether some of the reasons it was so challenging were self-inflicted, he said: "Definitely, yeah. When you have a chance to represent your country, you've got to give up six or eight weeks of your life, of living, training and behaving in a certain way. Unfortunately some people fell a little bit short of that. You can't afford to have that at that level. It hurts the group too much."

England were under siege from the first week of the tournament, after the Salford forward Gareth Hock was dropped from the squad for breaching the squad rules on alcohol, and the former captain James Graham was one of several other surprising absentees from their opening game against Australia, for reasons that were never explained. Sinfield's Leeds team-mate Zak Hardaker then withdrew before the last group game against Fiji for "personal reasons" which were later confirmed by the Rhinos as a disciplinary breach.

Sinfield, speaking at Leeds' media day before the start of the Super League season next week, fell well short of blaming England's semi-final defeat on those disciplinary issues. "I think we drew strength from it as well," he added. "It certainly didn't rip the camp wide open; if anything it brought us closer together. Without those things happening I don't know whether the squad would have been as tight. The group of players, 95% of everybody involved in that camp, was absolutely brilliant and shared something that has never been shared before at international level, at least when I've been a part of it. Something was built there that hopefully, if it's harnessed, there could be some special times not too far ahead."

Sinfield, 33, hopes he could be part of those special times, confirming that he will remain available to the England coach, Steve McNamara, for the Four Nations series in Australia and New Zealand at the end of this season – and welcoming McNamara's reappointment.

"Until you play, unfortunately that last game lingers; it sits with you a little while," he reflected. "So I'm looking forward to playing now. We weren't that far off but the reality is we got beat. That last 20 seconds hurt but we crack on from there and face the next challenge, get ready to get back on the field.

"If Steve feels I can do a job, I'm certainly available. It was important he kept the job. I think he's done a fantastic job over the last three years."

Sinfield will make his first appearance since Wembley in Leeds' only pre-season fixture against London Broncos at Headingley on Friday night, a testimonial match for their long-serving prop Ryan Bailey. The Rhinos coach, Brian McDermott, confirmed that Hardaker, who has publicly apologised for his World Cup conduct – unlike Hock – will start at full-back in that game, leaving Ben Jones-Bishop and the new signing Tom Briscoe apparently competing for one position on the wing.

McDermott also said he believed that the former England captain Jamie Peacock would be capable of playing beyond the end of the new contract he has signed with the Rhinos running until the end of 2015, when he will be almost 38. But Peacock insisted his date for retirement is now set and that he will play for only another two seasons.

"I'll have played 20 years as a professional player by then and I want to be a success in the rest of my life as well," he said. Like Sinfield, who has yet to open talks on an extension to his Rhinos contract which expires at the end of this season but talked of having several more seasons left in him, Peacock hopes to move into sports administration after retirement.